Medical lavage apparatus and methods

ABSTRACT

A medical lavage apparatus for body cavities comprising a housing having parallel irrigation and aspiration cylinders with captive plungers extending in bores thereof from a first end and pairs of check-valves positioned in parallel, smaller, offset cylinders located at second ends such that reciprocal movement of the each plunger in each cylinder performs the function of a one-way pump. The plungers are held captive and aligned by guide-stops proximally disposed in each cylinder. Each plunger comprises a seal disposed at the distal end thereof which inhibits communication between the pairs of check-valves in each cylinder when the plunger is fully seated in the cylinder. Novel jam-free dome shaped, slit check-valves are disposed to be the pair of check-valves in the aspiration cylinder in one embodiment and in irrigation cylinders as well in other embodiments. The dome shaped valves are described for use in other medical fluid control applications, as well. A septum formed of intersecting semi-circular-in-cross-section baffles joins the adjacent outer ends of the irrigation and aspiration check-valve cylinders so as to allow full fluid streams flowing from these outer ends to flow together at an angle. The septum and associated irrigation and aspiration check-valve cylinders are enclosed in a common exchange tube which leads to a common patient tube connecting nozzle. A special patient tube securing attachment is disposed on the connecting nozzle.

FIELD OF INVENTION

This invention relates broadly to medical lavage apparatus includingmedical valves and particularly to medical lavage apparatus comprisingat least one novel slit valve selectively accommodating one-way flow oflavage solution and/or other physiological liquids.

BACKGROUND AND RELATED ART

Lavage is defined as the washing out of hollow organs by copiousinjection and reinjection of liquid. Gastric lavages, for example, areused for a wide variety of medical situations including poisonings,upper GI bleeding, ulcers, etc. The normal current method of performingsuch a gastric lavage involves the insertion of a tube into a patients'sstomach through his nose or mouth.

According to principles disclosed in U.S. Pat. Nos. 4,842,581,4,872,866, and 5,049,135 one lavage apparatus for delivering lavagesolution quickly and efficaciously to a patient comprises a rigidhousing defining side-by-side parallel irrigation and aspirationcylinders in which plungers are inserted from first ends thereof. Theirrigation and aspiration cylinders have respective irrigation andaspiration check-valves at second ends thereof and inlet and outletcheck-valves at sides thereof. An anti-venturi septum extends to anintersecting line from the second ends of the cylinders. This septumcomprises two tapered, semi-circular-in-cross-section, baffles whichmeet at a sharp V-shaped apex which also forms a U-shaped intersectionline to provide a full opening between a separate common exchange tubeand both cylinders. The separate common exchange tube, with the commonnozzle is attached to the housing surrounding the second ends of thecylinders and said septum. The internal size of the nozzle is about thesame size as the inlet and outlet openings at the sides of thecylinders.

Check-valves disclosed in the above-mentioned U.S. Patents comprise flatresilient membranes attached to an exterior transverse wall of a valvebore which flex to open when pressure is exerted into the bore of thecheck-valve and return to a flat, closed disposition against thetransverse wall of the valve when pressure is exerted in an oppositedirection against the resilient membrane. One of the problems related tothe use of flat membrane check-valves, as noted in U.S. Pat. Nos.4,842,581 and 4,872,866, is jamming such as is caused by incompletevalve passage of non-liquid or high viscosity matter which is a commonby-product of lavage procedures. In an attempt to find a solution forthe jamming problem, flow orifice reducing shelves are installed in theflow path of the lavage solution upstream from the valves in order toallow larger surface-area membrane valves to be used because largersurface area flat membrane check-valves are not as susceptible tojamming as smaller surface area flat membrane check-valves.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION

One of the primary applications for this invention is in lavage devicessimilar to the apparatus disclosed in U.S. Pat. Nos. 4,842,581,4,872,866, and 5,049,135. In brief summary, this novel inventionalleviates known problems related to jamming in lavage deliveryapparatus by liquids containing non-liquid and high viscosity mattertrapped in flat membrane check-valves. While the instant inventioncomprises lavage apparatus and novel one-way valving structure therefor,the novel valving structure eliminates the need for special shelving andfor larger-than-flow orifice flat membrane check-valves in lavageapparatus.

The present invention embraces a lavage delivery apparatus comprising anovel one-way slit valve wherein highest velocity liquid flow occursgenerally across the valve. The lavage slit valve, in its preferredconfiguration, comprises a hollow dome-shaped flexible membranecomprising at least one but preferably two medially intersecting slits.The slit lips comprise smooth opposing parallel walls such that when apositive pressure differential is applied toward the convex side of thedome, the lips are pushed together to form a tight seal therebypreventing reversal of flow. Conversely, when a positive pressuredifferential is applied toward the concave side of the dome, the slitlips separate medially to accommodate one-way controlled flow.

Accordingly, it is a primary object to provide a medical lavageapparatus comprising a novel one-way slit valve which selectively passesa physiological liquid.

It is another primary object to provide a medical lavage apparatuscomprising a novel dome-shaped, one-way slit valve which functions as acheck-valve in an aspirating line.

It is another primary object to provide a medical lavage apparatuscomprising a novel dome-shaped, one-way slit valve which functions as acheck-valve in an inspirating line.

It is a principal object to provide a improved medical lavage syringeapparatus comprising guides for plungers reciprocated therein such thathandles attached to such plungers for manual reciprocation thereof areheld in a desired predetermined alignment at all times.

It is another principal object to provide a medical lavage apparatuscomprising a stop within a cylinder within which a plunger reciprocatesto prevent the plunger from being totally withdrawn from the cylinderduring operation.

It is a fundamental object to provide a medical lavage apparatuscomprising a slit valve defining a pathway for selective one-way liquidflow and check valve features preventing fluid flow in the oppositedirection.

These and other objects and features of the present invention will beapparent from the detailed description taken with reference toaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of the lavage apparatus of an embodiment of thisinvention with some parts illustrated diagrammatically;

FIG. 2 is an exploded perspective of the lavage apparatus of FIG. 1;

FIG. 3 is a perspective of a flat membrane check-valve;

FIG. 4 is a perspective of a dome-shaped, slit check-valve with partsbroken away for clarity;

FIG. 5 is a cross-section taken along lines 5--5 of FIG. 4;

FIG. 6 is a top view of the dome-shaped, slit check-valve of FIG. 4 in apartially open condition;

FIG. 7 is a top view of the dome-shaped, slit check-valve of FIG. 4 in aclosed condition;

FIG. 8 is a perspective of a plunger guide-stop;

FIG. 9 is a cross-section taken along lines 9--9 of FIG. 8;

FIG. 10 is a fragmentary perspective, with parts broken away for clarityof a port associated with a cylinder in the lavage apparatus of FIG. 1,with the dome-shaped, slit valve mounted in the port in a directioncausing the cylinder to be part of an inspirating pump;

FIG. 11 is a perspective of a housing comprising parts associated with aport attached to the cylinder shown in FIG. 10, with parts broken awayfor clarity, wherein the dome-shaped, slit valve is mounted in the portin a direction which causes the cylinder to be part of an inspiratingpump;

FIG. 12 is a fragmentary perspective of a line from a liquid source to apatient with some parts shown diagrammatically, the line having adome-shaped, slit check-valve disposed therein;

FIG. 13 is a cross-section taken along lines 13--13 of FIG. 2 of aportion of the distal end of a plunger and an associated seal used in acylinder of the lavage apparatus of FIG. 1; and

FIG. 14 is a cross-section of a seal taken along lines 14--14 of FIG. 2,the seal shown attached to a portion of a plunger.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In this description, the term proximal is used to indicate the segmentof the device normally closest to an operator or user of the device. Theterm distal refers to the other end. Reference is now made to theembodiments illustrated in FIGS. 1-14 wherein like numerals are used todesignate like parts throughout.

A lavage apparatus 10 is shown in FIG. 1 for use with a supply container12, supply tube 14, a waste container 16 and a waste tube 18. As betterseen in FIG. 2, lavage apparatus 10 comprises a rigid housing 20, acommon exchange tube 22 permanently affixed to housing 20 whenassembled, an irrigation plunger 24, an aspiration plunger 26, and asystem of seals and valves associated therewith.

Rigid housing 20 is preferably molded as one piece of medical grade,translucent styrene acrylonitrile plastic. Rigid housing 20 has anirrigation cylinder 28 defining an irrigation-cylinder bore 30, anaspiration cylinder 32, defining an aspiration cylinder bore 34, firstand second supporting flanges 36 and 38 holding together first ends ofirrigation and aspiration cylinders 28 and 32, a third flange 40 holdingtogether second ends of irrigation and aspiration cylinders 28 and 32,an inlet port 42 located near the second end of irrigation cylinder 28,an outlet port 44 located near the second end of aspiration cylinder 32,an irrigation check-valve cylinder 46 located at the end of irrigationcylinder 28 and an aspiration check-valve cylinder 48 located at thesecond end of aspiration cylinder 32 and an anti-venturi septum 50joining the second ends of irrigation and aspiration check-valvecylinders 46 and 48. As can be seen in FIGS. 1 and 2, first, second, andthird flanges 36, 38, and 40 hold irrigation cylinder 28 and aspirationcylinder 32 in a side-by-side, parallel, relationship. The bores 30 and34 of the respective irrigation and aspiration cylinders 28 and 32 arethe same size, each preferably providing approximately 160 cc's inactual stroke volume.

The inlet and outlet ports 42 and 44 are close to second ends 52 ofirrigation and aspiration cylinders 28 and 32, in the form of small,equal sized valve cylinders extending perpendicular to axes ofirrigation and aspiration cylinders 28 and 32. Such small sized valvecylinders increase the turbulence of fluid flow allowing for increasedmixing and dissolution of aspirated contents, thereby, reducingincompetence in valves which may be subject to jamming and clogging.

As seen in FIG. 2, equal sized irrigation and aspiration check-valvecylinders 46 and 48 are connected to their respective irrigation andaspiration cylinders 28 and 32 by tapered bonnets 54 and 56,respectively, so as to be close to, and parallel with, one another. Inthis respect, the circumference of check-valve cylinders 46 and 48 ispreferably about half that of irrigation and aspiration cylinders 28 and32 and their axes are offset from those of irrigation and aspirationcylinders 28 and 32 so that irrigation and aspiration check-valvecylinders 46 and 48 are close to one another with their bores alignedwith irrigation and aspiration cylinder bores 30 and 34.

Septum 50 has an irrigation baffle 58 and an aspiration baffle 60 eachof which is semi-circular in cross-sectional shape. These bafflesintersect at an outer tip 62 which forms a U-shaped line. In thisregard, septum baffles 58 and 60 are only positioned on the inside sidesof check-valve cylinders 46 and 48 so as to guide fluid from and tocheck-valve cylinders 46 and 48. A fourth flange 64 interconnects theouter ends of check-valve cylinders 46 and 48 and forms an oval withthese outer ends.

Plungers 24 and 26 are molded to be identical, each having shaftscomprised of crossed slats 66 and 68 supported by centrally disposedintermediate ribs 70 and end ribs 70'. Also molded integral therewithare finger-engaging handles 72 and seal mounting ribs 74. Eachseal-mounting rib 74 is separated from the nearest supporting rib 70' bya space 76 into which internally directed rib 78 of seal 80 is inserted(see FIG. 13). There are three cylinder bore contacting rings 83a, 83b,and 83c on the outer surface of seal 80.

It should be noted from FIGS. 1 and 2 that finger-engaging handles 72 ofplungers 24 and 26 are respectively turned so that they provide mirrorimages, one of the other. In this respect, finger-engaging handles 72are not symmetrical, being flat at first sides 86 thereof and rounded atsecond sides 88 thereof. The reason for this is so that the first sides86 can be as close together between two adjacent fingers as possiblewhere it is desirable to operate the syringes simultaneously. Thus,although the plungers are not connected, these finger engaging portionsare designed to allow easy use of one of the plungers individually orboth together, as is desired. This allows one to "prime the pump", so tospeak, with the irrigation half of the system prior to beginning alavage procedure.

As seen in FIG. 2, each cylinder 28 and 32 comprises two access holes86', 86", 88', and 88", respectively. A plunger guide-stop 90' isinserted into each access hole 86', 86", 88', 88" after each plunger 24and 26 has been inserted into each cylinder 28 and 32 during finalassembly. Referring to FIGS. 8 and 9, each plunger guide-stop 90'comprises a cap 90" having an inferior side 91' which has a curvaturewhich corresponds to the exterior curvature of cylinders 28 and 32. Fromthe inferior side 91' of cap 90" two legs 93' and 93" distend to form aU-shaped guide slot 95' therebetween.

Referring again to FIG. 2, portions of each intermediate rib 70 areremoved providing a free strip 95" along slat 68 about which legs 93'and 93" can pass unencumbered as each plunger 24 and 26 is reciprocatedwithin each respective cylinder 28 and 32. Note that such portions arenot removed from rib 70'. Thus, when guide-stops 90' are fully insertedinto access holes 86' and 88', each distal rib 70' engages an associatedguide-stop 90' as each plunger 24 and 26 is withdrawn proximally tocause plungers 24 and 26 to be permanently retained in cylinders 28 and32. Further, each slat 68 is disposed between at least one pair of legs93' such that rotational travel of each plunger 24 and 26 is limited,thereby keeping handles 72 relatively disposed as seen in FIG. 1.

As part of the assembly of lavage apparatus 10, seals 80 are attached toeach plunger 24 and 26 which is inserted into each cylinder 28 and 32and handles 72 are oriented as seen in FIG. 2. When handles 72 are sooriented, slats 68 align with holes 86', 86", 88' and 88" in eachrespective cylinder 28 and 32. Legs 93' and 93" of one guide-stop 90'are inserted into each hole 86', 86", 88', and 88" such that eachU-shaped 95' guide slot engages slat 68. Each guide-stop 90' ispermanently affixed to each cylinder 28 and 32 by sonic welding or byadhesive techniques well known in the art. Each guide-stop 90' ispreferably made from the same material as used for cylinder's 28 and 32and formed by injection molding.

The common exchange tube 22 is oblong, or oval, in cross section as canbe seen in FIGS. 1 and 2 to thereby form an oblong chamber in whichfluid flows to and from irrigation and aspiration cylinders 28 and 32.The common exchange tube 22 includes an apron portion 90, a manifoldportion 92, a common nozzle portion 94, and an attachment ridge 96.Attachment ridge 96 is of a size to sealingly fit about the side-by-sideirrigation and aspiration check-valve cylinders 46 and 48 and the fourthflange 64 which joins them. In use, these members are preferably joinedtogether by sonic welding or by an adhesive. The apron portion 90 makesthe entire apparatus more streamlined in appearance and for handling,however, it is not necessary for operation of the lavage apparatus.

Manifold portion 92 encloses and seals with outer ends 98 and 100 ofirrigation and aspiration check-valve cylinders 46 and 48 as well asseptum 50 so that all material flowing to and from outer ends 98 and 100are guided by septum 50 and manifold portion 92. Similarly, all fluidsflowing to and from manifold portion 92 flow through common nozzle 94.It should be noted that septum 50 is so arranged and designed that fluidstreams flowing from irrigation check-valve cylinder 46 is directed intonozzle 94 and fluid flowing from nozzle 94 is directed to aspirationcheck-valve cylinder 48 without restriction and without causing undueturbulence. In this manner, such fluid streams are not caused to crossmix. The U-shaped outer tip line 62 particularly aids in avoiding unduecross mixing by not causing a venturi restriction to create a negativepressure in manifold portion 92 which improperly opens a check-valve.Sidewalls of septum 50 press against interior surfaces of the manifoldto create a seal therebetween.

To assure a secure attachment to a patient connection tube (not shown)nozzle 94 comprises a tube retaining apparatus 94' seen in FIGS. 1, 2,and 14. Referring to 14, tube retaining apparatus 94' is therein seen incross section. Tube retaining apparatus 94' comprises two identicalmolded, sections 97 and 97' 97 and 97' are identical, only one section97 will described in detail.

Tube retaining apparatus 94' is attached to nozzle 94 through anoffsetting ring 97" which encircles nozzle 94 and provides attachmentfor both sections 97 and 97'. Distending proximally from offsetting ring97" is an ear-shaped part 99 which is shaped for engagement by anoperator's thumb and fingers. Extending distally from offsetting ring97" is a tube engaging part 99' which is shaped to engage the patienttube when disposed upon nozzle 94. A strengthening member 100' isdisposed between parts 99 and 99' to transfer at least a portion of theforces exerted upon part 99 to part 99'. So disposed, when parts 99 ofboth sections 97 and 97' are forced inward, by squeezing such as by athumb and forefinger, parts 99' are moved away from nozzle 94 to permitthe patient connection tube to be facilely connected thereto. Afterinsertion of the patient connection tube, the compressive force againstsections 97 and 97' is released and each part 99' compressively engagesthe patient connection tube. A secure engagement is further secured by aplurality of grooves 100" molded into each part 99' to act as teethwhich bite into the patient connection tube to better secure the patientconnection tube after release of parts 99'.

With regard to the check-valves, two different types of check-valves areseen in the embodiment of FIG. 2. A first check-valve 102, valve 101,comprising a flat, resilient membrane 104 is disposed in inlet port 42of irrigation cylinders 28. A second, like check-valve 102, valve 101',is disposed in irrigation check-valve cylinder 46. Each check-valve 102is oriented with each cylinder 28 and 46 in a direction permissive tofluid flow toward nozzle 94.

As seen in FIG. 3, each check-valve 102 has a cylindrical outer wall102" with a planar cylindrical edge 103 and cross wall struts 104'carrying resilient membrane 104. Between cross wall struts 104', aplurality of membrane supporting tines 104" project radially inward fromouter wall 102". In combination, planar cylindrical edge 103, cross wallstruts 104', and tines 104" define a membrane supporting planar surface103'.

Referring again to FIG. 2, as an example of check-valve 102 operation,resilient membrane 104 on valve 101' flexes open when pressure isexerted from the irrigation cylinder bore 30 toward nozzle 94 but closeswhen pressure is exerted in the opposite direction. It should be notedthat flow through an open check-valve 102 courses radially outwardacross surface 103' and around a peripheral edge 105 of membrane 104.Thus flow about membrane 104 is a relatively thin stream, cylindricallydisposed about the outer edge 105 of membrane 104, best seen in FIG. 3.Any material resident upon surface 103' when membrane is forcedthereagainst to close check-valve 102 can cause check-valve 102 to beincompetent. Such problems are not common for irrigation solutions, butwhen physiological debris is recovered from a patient during a lavageprocedure, solid or highly viscous matter is commonly carried inaspirated solutions. For this reason, flat membrane check-valves are notas effective in aspirating pathways as in inspirating pathways of lavageapparatus.

For this reason in the embodiment seen in FIG. 2, a first dome-shaped,slit check-valve 106, valve 106", is used in aspiration check-valvecylinder 48 to restrictively control flow only into cylinder 32.Dome-shaped, slit check-valve 106 comprises novel non-jamming featuresmore particularly qualified for use in check-valve applicationsinvolving valving solutions comprising physiological debris. A detaileddescription of dome-shaped, slit valve 106 is provided hereafter. Asecond dome-shaped, slit check-valve 106, valve 106', is disposed inoutlet port 44 to serve as a physiological debris containing solutionvalve in the same manner and direction as valve 106".

As mentioned earlier, valve 101' is disposed in irrigation check-valvecylinder 46 and allows fluid to flow into irrigation cylinder 28, butdoes not allow flow from irrigation cylinder 28. Outlet valve 106"allows fluid flow from aspiration cylinder 32, however, it does notallow flow into cylinder 32. Funnel-like inlet and outlet adapters 116and 118 are respectively attached to inlet port 42 and outlet port 44.

Regarding inlet and outlet ports 42 and 44, each port 42 and 44preferably comprises a diametral opening substantially the same size asports irrigation check-valve cylinder 46 and aspiration check-valvecylinder 48 such that valves may be used interchangeably in ports 42 and44 and check-valve cylinders 46 and 48, as appropriate. Ports 42 and 44open unobstructedly into cylinder bores 30 and 34, respectively. Theapproximate matching of the sizes of ports 42 and 44 and check-valvecylinders 46 and 48 balances pressures within the system so as to avoidimproper opening check-valves during operation and thereby avoid crossmixing of contaminated and pure fluids.

Referring once more to FIG. 13, the distance between rings 83a and 83cis sufficient to cover each associated port 42 and 44 when eachrespective plunger 24 and 26 is fully seated in the respective cylinderbore 30 and 34, allowing ports 42 and 44 to be fully sealed by seal 80.Through the use of dome-shaped, slit check-valves 106, a previouslytaken precaution of shelving in each port opening between a port 42 or44 and a respective cylinder bore 30 or 34 in embodiments of similarlavage apparatus is not required.

In manufacture of the lavage apparatus of this invention, rigid housing20, two plungers 24 and 26, the common exchange tube 22 (assembled to bea part of the housing), and the various cylinders of the twocheck-valves 102 and 106, and inlet and outlet adapters 116 and 118 aremolded of hard resinous plastic. In this respect, all of thecheck-valves are of the same size to eliminate undue proliferation ofmolds for these elements. All of the rigid components of this inventioncan be made of a rigid hard resinous plastic such as styreneacrylonitrile.

Plunger seal 80 and the various check-valve membranes are molded, orpurchased off-the-shelf of pliant synthetic resinous material. Thedome-shaped, slit membrane material and method of manufacture isdescribed in detail hereafter. The plunger seals 80 are attached toplungers 24 and 26 and. as seen in FIG. 3, membranes 104 are attached byoutwardly distending portions 102' of knobs 105' medially disposed oncheck-valve 102 cross wall struts 104'. Exteriors of cylinders ofcheck-valves 102 and check-valves 106 are preferably attached by sonicwelding into rigid housing 20 in their respective positions as isdepicted in FIG. 2. After attachment of check-valves 102 and 106, asappropriate, attachment ridge 96 of common exchange tube is sealinglyadhered to irrigation and aspiration check-valve cylinders 46 and 48 andflange 64 which adjoins these two ridges, also preferably by sonicwelding. As seen in FIG. 1, the various valves cannot be easilyserviced, but that is not necessary since the lavage apparatus isdesigned to be a single use disposable product.

To utilize lavage apparatus 10, one places a saline liquid in supplycontainer 12 which is joined via a supply tube 14 and inlet adapter 116to inlet port 42. See FIG. 1. The waste container 16 is similarlyattached via tube 18 and outlet adapter 118 to outlet port 44. Thesaline solution is to be instilled into a body cavity, left for a shortlength of time and then sucked out. A tube (not shown) is attached tonozzle 94 of the common exchange tube 22 and is inserted through anopening in the human body of a patient 119 in the direction of arrow119' into an organ to be lavaged. Where fluid from more than oneirrigation cylinder 28 is to be inserted into the organ before any isaspirated, aspiration plunger 26 is driven completely into aspirationcylinder 32 as is depicted in FIG. 1. In this position, aspirationplunger seal 80 completely seals outlet port 44. Thus, while theaspiration plunger 26 is left in this position, no fluid can flowthrough outlet port 44. With aspiration plunger 26 so situated, theirrigation plunger 24 is pulled outwardly to cause a vacuum in theirrigation cylinder 28. This vacuum respectfully opens membrane 104 ofinlet check-valve 101 and closes membrane 104 of check-valve 101'. Thusfluid is drawn from supply container 12 into irrigation cylinder 28.Thereafter, irrigation plunger 24 is driven into irrigation cylinder 28which closes inlet check-valve 101, opens irrigation check-valve 101',and drives fluid out of irrigation cylinder 28 into manifold portion 92of common exchange tube 22 and out nozzle 94 of common exchange tube 22.In this respect, irrigation baffle 58 of septum 50 guides the outwardlyflowing fluid to ensure that it enters nozzle 94 rather than beingdriven through aspiration check-valve cylinder 48 to open aspirationcheck-valve 106" and thereby drive plunger 26 from its blockingposition. The irrigator plunger 24 is moved in and out, functioning as apump, until the body cavity is filled with the right amount of fluid.

After the irrigation fluid has been left in the body organ for a periodof time, irrigation plunger 24 is driven fully into irrigation cylinder28 so seal 80 covers port 42 thereby not allowing flow of fluid throughport 42. Once irrigation plunger 24 is so seated, aspiration plunger 26is pulled and pushed in, thereby drawing contaminated fluid from thebody organ through nozzle 94, and aspiration check-valve cylinder 48,into aspiration cylinder 32 during the pull and driving contaminatedwaste fluid out of port 44 and into waste container 16 during the push.

Ordinarily, most body organs requiring lavage will be of such size as tohold multiple loads of irrigation cylinder 28, with the skill of anoperator protecting against over distension of a cavity. Once theappropriate amount of irrigant is instilled, irrigation and aspirationplungers 24 and 26 are gripped together and moved in and outsimultaneously thereby maintaining a constant steady-state volume offluid flow into and out of the organ. On the out strokes irrigationcylinder 28 is loaded with fresh fluid from supply container 12 andaspiration cylinder 32 is loaded with contaminated, physiological debriscontaining waste solution from the organ. On in strokes, the fresh fluidin irrigation cylinder 28 is forced into the organ and contaminatedwaste fluid in aspiration cylinder 32 is forced toward and into wastecontainer 16. During these strokes, since ports 42 and 44 have the samecross-section size as the internal bore of nozzle 94, the pressuresapplied at each of these by the equal size plunger 24 and 26 areapproximately equal, there being only a small drop across each of thevarious valves to cause them to act as check-valves in the appropriatedirections. Similarly, the shape of the U-shaped outer tip line 62 ofseptum 50 does not cause undue venturi or eddy effects which createundue changes in pressure at nozzle 94 to improperly open irrigation andaspiration check-valves 101' and 106" to cause mixing.

A unique feature of the design of this lavage apparatus is that it canbe used to clear itself of debris. In this regard, the most likelyocclusion will occur on the aspiration side of the device because it isthe part which is exposed to particulate matter. If a clog shoulddevelop, one can clear it by pulling back on aspiration plunger 26 untiloutlet port 44 is open, crimping of the tube attached to nozzle 94, andpumping irrigation plunger 24 in and out to force fresh fluid throughaspiration check-valve 106" and outlet check-valve 106'. The tubeattached to nozzle 94 can be cleared by pushing aspiration plunger 26fully forward to seat and close port 44, followed by forcefullyoperating irrigation plunger 24.

A significant improvement in lavage apparatus operation as a result of areduction in need to clear debris from valves and improved operationalvalve competency while operating an lavage produced physiologic debriscontaining solution environment is accrued through use of check-valveswhich open a medially disposed pathway to fluid flow rather than apathway about a planar edge as is true of flat membrane valve 102. Asdescribed earlier, such check-valves 106 are used in the embodiment seenin FIG. 2 as valves 106' and 106". Magnified views of check-valve 106are seen in FIGS. 4-7.

As seen in FIG. 4, valve 106 comprises a slit membrane surroundingcylindrical housing 200. Housing 200 comprises an outer cylindricalsurface 202, a top circular edge 204, an inner cylindrical surface 206,and a bottom circular edge 208. While surface 20 is smooth and ofuniform diameter for being inserted and affixed to an inward disposedsurface such as to a port 44, inner surface 206 comprises a series ofsteps and grooves such that circular edge 204 is thinner in radial widththan edge 208. As seen in FIG. 4, inner surface 206 comprises a surfaceof revolution which comprises a side wall 210 which departs from edge204 travelling parallel to outer wall 202 to a radially inwardlyprojecting ledge 212 which is truncated by a second parallel surface 214which is parallel to outer wall 202. More proximal to edge 208, parallelsurface 214 intersects with a surface 216 radially distending outwardlytherefrom. Surface 216 intersects with a third parallel surface 218which is parallel to outer wall 202. Surface 218 is truncated by asurface 220 which radiates inwardly from surface 218 to a fourthparallel surface 222 with is parallel to outer wall 202. So disposed,surfaces 216, 218, and 220 form a retaining groove for a dome shaped,slit valve membrane 230.

As best seen in FIG. 4, dome shaped, slit valve membrane 230 comprises abase 232, a hollow cylindrical side wall 234, and a hollow dome 236. Asseen in FIGS. 4 and 5, base 232 comprises an anchoring ring 238 whichextends radially outward from side wall 234, is formed and shaped to fittightly within the groove formed by surfaces 216, 218, and 220 and ishermetically secured in housing 200 by insertion into the groove formedby surfaces 216, 218, and 220.

From base 232, membrane 230 is seen in FIG. 4 to extend upward to formcylindrical side wall 23 to which is attached enclosing dome 236. Dome236 comprises at least two intersecting slits 240 and 242, whichpreferably intersect medially at the top of dome 236 at right angles.Each slit 240 and 242 comprises a pair of smooth, planar, opposing lips244, 246, 248, and 250, respectively, best seen in FIG. 6. Referringbriefly to FIG. 5, dome 236 comprises a hollow, circular concave innersurface 252 and an outer convex surface 254 which is circularly parallelto surface 252. As best seen in FIG. 7, when a positive pressure isexerted upon surface 254, opposed lips 244, 246, 248, and 250 are forcedclosed by a radial force vector of the surface imposed pressure whilethe dome shape of membrane 230 resists eversion, even to pressures whichare large compared pressures exerted during a lavage procedure.

As seen in FIG. 6, when a positive pressure is applied to inner surface252, lips 244, 246, 248 and 250 are forced apart, creating a centrallydisposed orifice which is permissive to flow therethrough. As is wellknown in the art of fluid flow, fluid flow velocity is higher, thefarther away from a wall fluid is flowing in a tube. As such, it hasbeen shown that the best valve for transport of physiologic debriscarrying solutions is one which opens widely and centrally to permitsolution to medially flow across the valve with highest possiblevelocity. Also, as membrane 230 presents a slick, surface with nearlyunattachable edges of lips 244, 246, 248, and 250, jamming of valve 106due to solids or high viscosity liquids in contact therewith is rare,making use of membrane 230 ideal for valving of physiological debriscarrying solutions.

Housing 200 may be made by injection molding and may be made from rigidsynthetic resinous material such as the material from which housing 20is made. Membrane 230 may be made from a flexible, resilient syntheticresinous material such as KRATON, a product of GLS Plastics, 740 B,Industrial Park, Carey, Ill., 60013. Membrane 230 is preferably made byinjection molding with each slit 240 and 242 being individually cuttherein by using a razor sharp blade which cuts one slit of the membraneat a time while residing upon a membrane 230 form-fitting tool whichcomprises slits matching the width and direction of cut of the sharpblade.

It can be appreciated by those skilled in the art that the lavageapparatus described herein is relatively easy to manufacture and use butyet allows non-messy lavaging of organs. Medical personnel can performlavage procedures without the lavage liquid escaping outside the systemand therefore not contaminating lavage personnel, a patient, norsurrounding areas and not otherwise causing an unsanitary ordisagreeable problem.

The designs of smaller, offset, irrigation and aspiration check-valvecylinders 46 and 48, pointed plunger seals 80 and the common exchangetube 22 which is welded directly to housing 20 creates a minimum of"dead space" between irrigation and aspiration check-valve cylinders 46and 48 and nozzle 94 which improves pumping efficiency.

The design of septum 50 prevents undue eddy and venturi effects.

In another embodiment of the invention, a valve 106 is used to replacevalve 102 in port 42 as seen in FIG. 11. As valve 106 comprises ahousing 200 which is substantially the same size as outer wall 102",replacement is a direct one-to-one substitution.

In yet another embodiment of the invention a valve 106, is used insteadof valve 102 in irrigation check-valve cylinders 46 as seen in FIG. 10.As is the case in the embodiment of FIG. 11, valve 106 is a directreplacement for valve 102 in this embodiment as well.

A different application for valve 106 is seen in an embodiment shownFIG. 12 wherein a valve 106 is used in a medical line 258 from a source260 to a patient 262. Connections and fluid flow from source 260 to line258 and from line 258 to patient 262 are symbolized by arrows 264 and266, respectively. As seen in FIG. 12, valve 106 is disposed in line 258in a direction permissive to flow from source 260 to patient 262. Sodisposed, valve 106 blocks block bleed back when line 258 transmits ahigher than source pressure from a vessel or cavity in patient 262.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:
 1. Aliquid and physiological debris aspirating apparatus comprising:anaspirating syringe comprising an aspirating cylinder and an aspiratingplunger, the cylinder being associated with a liquid and debris influentport and a liquid and debris effluent port; at least one of said portscomprising a one-way physiological debris-passing slit valve comprisinga dome-shaped diaphragm having a convex surface and a concave surface,the diaphragm comprising at least one curvilinear slit disposed betweenthe convex and concave surfaces and comprising normally closedcontiguously abutting slit edge surfaces which remain contiguousresponsive to pressure applied to the convex surface of the diaphragmand which slit edge surfaces separate from each other responsive topressure applied top the concave side of diaphragm due to manualmanipulation of the aspirating plunger in respect to the aspiratingcylinder to open the diaphragm to accommodate flow of liquid andphysiological debris between the separated slit edge surfaces.
 2. Amedical lavage apparatus for irrigating and aspirating a body cavity ofa patient comprising:a liquid irrigation cylinder and plunger, theirrigation cylinder comprising a liquid influent port and a liquideffluent port; liquid and physiological debris aspiration cylinder andplunger, the aspiration cylinder comprising a liquid and debris influentport and a liquid and debris effluent port; a one-way valve disposed atat least one of the liquid and debris influent and effluent ports, saidone-way valve comprising an elastomeric bulbous-shaped slit valve havingmemory comprising at least one curvilinear slit comprising normallyclosed contiguously opposed directly abutting lips comprising lip edgeswhich lip edges are separated by pressure applied to one side of thebulbous slit wave, the pressure being caused by manual manipulation ofthe aspirating plunger, to open the slit lips counter to the memorythereby accommodating flow of liquid and debris through the open lips,the memory closing the lip edges again into said contiguously closedopposed directly abutting disposition when said pressure is removed. 3.A medical lavage apparatus according to claim 2 wherein one of saidone-way elastomeric bulbous-shaped slit valves is disposed in both theliquid and debris influent port and the liquid and debris effluent port.4. A medical lavage apparatus according to claim 2 wherein one of saidone-way elastomeric bulbous-shaped slit valves is disposed at one of theliquid influent and liquid effluent ports of the irrigation cylinder. 5.A medical lavage apparatus according to claim 2 wherein one of saidone-way elastomeric bulbous-shaped slit valves is disposed at both ofthe liquid influent and liquid effluent ports of the irrigationcylinder.
 6. A medical lavage apparatus according to claim 2 furthercomprising a nozzle with a single liquid flow passageway for theeffluent of the irrigation cylinder and the influent of the aspiratingcylinder and a clamp by which a liquid and debris flow tube to thepatient is releasibly clamped to the nozzle.
 7. A lavage apparatuscomprising:a source of medical irrigating fluid; one piston/cylinder bywhich medical irrigating liquid from the source is selectivelyintroduced into a body cavity of a medical patient; a secondpiston/cylinder defining a flow path by which liquid and physiologicaldebris is aspirated from said body cavity and discarded; at least onerounded normally closed one-way slit valve diaphragm disposed in saidflow path, the diaphragm comprising at least one curved slit comprisingnormally closed opposed contiguous slit edges which become more tightlyclosed when pressure is applied to the diaphragm in one direction andwhich slit edges yawn apart to define an opening when pressure isapplied to the diaphragm in another direction to accommodate facile flowof liquid and physiological debris through the opening.
 8. A lavageapparatus according to claim 7 wherein the diaphragm comprise two ofsaid curved slits, which slits intersect near an apex of the roundeddiaphragm.